Pectus excavatum

Pectus excavatum is a deformity of the sternum where the sternum protrudes inward. It’s the most common deformity of the anterior chest wall. It’s mostly idiopathic but may be associated with connective tissue disorders like Marfan syndrome. It’s more common in males. It's sort of the opposite of pectus carinatum.

May be present at birth (at which case it usually worsens during the rapid growth of adolescence), or it may occur later. The deformity is mostly a cosmetic problem, but in compression of the lung may cause dyspnoea, decreased exercise intolerance, atelectasis, and recurrent respiratory infections. The chest wall may be asymmetric.

Diagnosis and evaluation

To evaluate the severity during consideration for surgery, a CT scan must be made to calculate the Haller index (pectus severity index). See this image for details. Two distances in the thoracic cavity are measured (A and B), and the Haller index is calculated as A/B. A Haller index of > 3,5 is an indication for surgery.

Management

The optimal time for surgery is the age of ~15. Surgery is not performed at much younger ages due to the importance of being able to follow instructions regarding the postoperative period (not lifting heavy, no sports, etc.). Surgery is not performed after age of 30 due to rigidity of the chest wall.

Surgery involves implantation of a metal bar just underneath the sternum, which elevates it. This procedure is called the modified Nuss operation. Each lung is intentionally collapsed sequentially during the operation to prevent the metal bar from puncturing it. The procedure is guided by video, achieved by inserting a camera through the chest wall. Elevation of the sternum with a metal bar is possible due to the soft cartilages of children. The metal bar is removed 2 – 3 years later (as it cannot grow with the body).

Possible complications of surgery include dislocation of the metal bar, haemothorax, etc.

If surgery is not indicated, the patient should receive physiotherapy and exercises to grow the chest wall muscles, which will improve the deformity.